Top Spring Programming Questions and Answers for 2024

• Answer: The Spring Framework is a comprehensive open-source framework for Java, used for building enterprise-grade applications. It provides features like dependency injection, AOP, and MVC architecture, facilitating easier, modular, and testable development.

2. What is Dependency Injection (DI) in Spring?

• Answer: DI is a design pattern where the Spring container injects dependencies into objects, rather than the objects managing their dependencies. It promotes loose coupling and makes code more modular and testable.

3. Explain Inversion of Control (IoC).

• Answer: IoC is a principle where control of objects is transferred to a container, like the Spring IoC container, which manages object lifecycle and dependency injection, rather than objects managing dependencies directly.

4. What is the difference between BeanFactory and ApplicationContext?

• Answer: BeanFactory is the basic container for managing beans, while ApplicationContext is a more feature-rich container offering additional features such as event propagation, AOP, and application-layer-specific context.

5. What are the different types of Dependency Injection in Spring?

• Answer: Spring supports constructor-based DI, where dependencies are injected via a class constructor, and setter-based DI, where dependencies are injected through setter methods.

6. What is a Spring Bean?

• Answer: A Spring Bean is an object that is instantiated, assembled, and managed by the Spring IoC container. Beans are defined in the configuration file or annotated with @Component or similar annotations.

7. What is the purpose of the @Autowired annotation?

• Answer: @Autowired is used to enable automatic dependency injection in Spring. It can be applied to constructors, fields, or methods, and tells the container to inject the required bean.

8. What is Spring MVC?

• Answer: Spring MVC is a module within the Spring Framework that follows the Model-View-Controller (MVC) architecture, enabling developers to build web applications in a highly organized and structured manner.

9. What is Aspect-Oriented Programming (AOP) in Spring?

• Answer: AOP in Spring allows separation of cross-cutting concerns, such as logging or security, from business logic. It uses concepts like aspects, join points, and advice to modularize these concerns.

10. Explain different types of Advice in Spring AOP.

• Answer: The types of Advice are:
  • Before Advice: Runs before a method.
  • After Advice: Runs after a method, regardless of its outcome.
  • After Returning Advice: Runs after a method if it completes successfully.
  • After Throwing Advice: Runs if a method throws an exception.
  • Around Advice: Wraps around a method and has control over its execution.

11. What is a Proxy in Spring AOP?

• Answer: A proxy is an object created by AOP to add functionality to target methods at runtime. Spring creates proxies using JDK dynamic proxies or CGLIB proxies for classes or interfaces.

12. What is @Component in Spring?

• Answer: @Component is a generic stereotype annotation for beans. Spring scans classes with @Component and manages them in the context, similar to XML-defined beans.

13. What is Spring Boot, and how does it relate to Spring?

• Answer: Spring Boot is an extension of Spring Framework that simplifies setup with embedded servers, auto-configuration, and reduced XML configuration, allowing rapid development of Spring-based applications.

14. How does Spring handle transactions?

• Answer: Spring provides declarative transaction management using @Transactional annotation and supports programmatic transaction management through TransactionTemplate and PlatformTransactionManager.

15. What is the @RequestMapping annotation used for?

• Answer: @RequestMapping is used in Spring MVC to map HTTP requests to handler methods of MVC and REST controllers. It can handle GET, POST, PUT, DELETE, etc., requests based on parameters.

16. Explain the Spring Data JPA module.

• Answer: Spring Data JPA simplifies data access by abstracting database operations. It provides a repository-based programming model that allows developers to define queries by method names.

17. What are Spring Profiles?

• Answer: Spring Profiles allow developers to define beans for different environments, such as development, testing, and production. Profiles can be activated based on environment-specific needs.

18. What is @RestController in Spring?

• Answer: @RestController is a combination of @Controller and @ResponseBody that simplifies the creation of RESTful web services by automatically converting response data to JSON or XML format.

19. Explain Spring Initializr and its purpose.

• Answer: Spring Initializr is a web-based tool that generates Spring Boot project templates with minimal configuration. It helps set up project dependencies and initial structure.

20. What are Spring Security and its main features?

• Answer: Spring Security is a module that provides authentication, authorization, and other security features. It supports methods like Basic Auth, OAuth, JWT, and password encryption, offering fine-grained security for applications.

Spring Programming Questions – Conclusion

Mastering the Spring Framework and understanding its core features, such as dependency injection, AOP, Spring MVC, and Spring Boot, is essential for Java developers aiming to work on enterprise-level applications. The questions and answers provided in this guide cover a broad range of topics to help you understand both fundamental and advanced aspects of Spring. Familiarity with these concepts will not only help you excel in interviews but also equip you to develop scalable, secure, and efficient applications using Spring. With practice and an in-depth understanding, you’ll be well-prepared to leverage Spring’s powerful capabilities in real-world projects.